*

The status for Australia’s stocks of Endeavour Prawns varies by species across jurisdictions depending on the availability of catch and abundance information.  Where there is adequate information for assessment, such as in the main commercial fisheries, they are considered to be sustainable. Otherwise, where less information is available, they are classified as undefined.

Endeavour Prawns includes two species, Blue Endeavour Prawn Metapenaeus endeavouri, and Red Endeavour Prawn M. ensis that are generally not distinguished in fisheries. Although the two species are caught in differing proportions in different regions.

Endeavour Prawn fisheries are located in Shark Bay, Exmouth Gulf, the north coast of Western Australia, the Gulf of Carpentaria, the Torres Strait and the east coast of Queensland. Little is known about the biological stock structure of the populations of Blue and Red Endeavour Prawns that make up these fisheries. The majority of catch reported in this chapter is Blue Endeavour Prawn. Red Endeavour Prawn represents less than 20% of the catch in the East Coast Otter Trawl Fishery [Turnbull and Atfield 2007] and between 20–40% in the Northern Prawn Fishery.

Here, assessment of stock status is presented at the management unit level—Northern Prawn Fishery (Blue Endeavour Prawn), Northern Prawn Fishery (Red Endeavour Prawn), Torres Strait Prawn Fishery (Blue Endeavour Prawn) (Commonwealth); Exmouth Gulf Prawn Managed Fishery (Blue Endeavour Prawn), North Coast Prawn Managed Fishery (Blue Endeavour Prawn), Shark Bay Prawn Managed Fishery (Blue Endeavour Prawn) (Western Australia); and East Coast Otter Trawl Fishery (Red and Blue Endeavour Prawn) (Queensland).

Northern Prawn Fishery (Blue Endeavour Prawn)

Blue Endeavour Prawn is a by-product of fishing for Tiger Prawns, and so catches are linked to changes in effort targeting Tiger Prawns. Blue Endeavour Prawn is assessed as part of the integrated bio-economic model for the Northern Prawn Fishery (Commonwealth) Tiger Prawn sector [Deng et al. 2022]. Commercial catch of Endeavour Prawn is disaggregated into separate species using a model incorporating historical fishery-independent survey data [Venables and Dichmont 2004]. The stock assessment for the Tiger Prawn fishery uses a multispecies approach, with a weekly, sex- and size-structured population model for brown and Grooved Tiger Prawns, and a Bayesian hierarchical production model for Blue Endeavour Prawn [Punt et al. 2011]. This bio-economic stock assessment model provides annual estimates of MSY and MEY [Punt et al. 2010]. The model looks seven years ahead towards the MEY and MSY targets, using updated spawning/recruitment survey results, catch/effort data and fishery economic information, but dampens year-to-year effort changes that may arise from high recruitment variability or fishing constraints. Species-level components of MSY and MEY, based on estimated effort for each species, are taken from this overall model. Full stock assessments are undertaken every 2 years, with logbook data collected continuously in intervening years. In addition, annual fishery-independent monitoring in the Gulf of Carpentaria provides Prawn size data and indices of abundance by species that are input to the assessment [Kenyon et al. 2021]. The most recent Tiger Prawn fishery assessment covers catch and effort up to 2021 [Deng et al. 2022].

The base-case estimate of the size of the Blue Endeavour Prawn spawning stock at the end of 2021 as a proportion of spawning stock size at MSY (SB2021/SBMSY) was 0.65 (range across sensitivities 0.61–0.82). Further, the 5-year average of spawning stock size as a proportion of spawning stock size at MSY was 0.66 and above the agreed limit reference point (LRP) of 0.5SBMSY. The base-case estimate of the size of the spawning stock as a proportion of spawning stock size at MEY (SB2021/SBMEY) was 0.57 (range across sensitivities 0.52–0.76), a decrease from 0.86 in the last stock assessment [Deng et al. 2022].  

Catch at MSY along the modelled path to the 7-year MSY target for Blue Endeavour Prawn was estimated to be 787 t [Deng et al. 2022], while catch at MEY along the path to the MEY target was estimated to be 659 t [Deng et al. 2022]. Effort in terms of MEY or MSY is not estimated for Blue Endeavour Prawn because this species is a by-product of targeting Tiger Prawns. Since 2002, annual catches have averaged around 280 t. Catch in 2021 was 266 t, up from 233 t in 2020 and both well below MEY and MSY and considered unlikely to drive stocks below the LRP [Butler et al. 2022].  

A new Bayesian stock assessment approach has been developed specifically for Endeavour Prawns to better deal with the relatively low information about these by-product species [Zhou et al. 2023]. However, the results from the 2021 Tiger Prawn stock assessment for Blue Endeavour Prawn were considered acceptable by NPFRAG for management. The 2021 Tiger Prawn assessment uses more recent data than the new Bayesian approach. Therefore, the 2021 Tiger Prawn assessment is used for status determination purposes for Blue Endeavour Prawns in 2022 [Butler et al. 2023].

The Integrated Monitoring Program’s 2022 preseason recruitment surveys indicate low relative post-recruitment abundance for Blue Endeavour Prawn, the second lowest after 2004 seen in the data series (2003–22) [AFMA 2022].

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, the above evidence indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the Northern Prawn Fishery (Blue Endeavour Prawn) (Commonwealth) management unit is classified as a sustainable stock.

Northern Prawn Fishery (Red Endeavour Prawn)

Red Endeavour Prawn is caught as a by-product of effort directed at Tiger Prawns. Catches of Red Endeavour Prawn in recent years (155 t in 2022, 170 t in 2021 and 125 t in 2020) have been low compared with historical highs [Butler et al. 2023]. This is most likely related to the overall decline in fishing effort directed at Tiger Prawns, and area and time closures affecting areas where Red Endeavour Prawn were historically targeted, rather than being an indication of a fall in Red Endeavour Prawn biomass.

A new stock assessment approach has been developed specifically for Endeavour Prawns to better deal with the relatively low information about these by-product species [Zhou et al. 2023]. It was recently accepted by NPFRAG [AFMA 2023]. For Red Endeavour Prawns, this assessment uses newly updated growth information [Zhou et al. 2022]. The new method uses a single stock Bayesian approach in a biomass dynamics model (surplus production model), using raw catch data up to 2020. The estimated median size of the Red Endeavour Prawn stock in 2020 as a proportion of stock size at MSY (B2020/BMSY) was 1.20. The estimate of median fishing mortality of the Red Endeavour Prawn stock in 2020 as a proportion of fishing mortality at MSY (F2020/FMSY) was 0.21. Since then, catch has remained low and this level of fishing mortality is unlikely to cause the stock to become recruitment impaired [Butler et al. 2023].  

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, the above evidence indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the Northern Prawn Fishery (Red Endeavour Prawn) (Commonwealth) management unit is classified as a sustainable stock.

Torres Strait Prawn Fishery (Blue Endeavour Prawn)

Blue Endeavour Prawns are mostly caught as byproduct when targeting Tiger Prawns. The last Blue Endeavour Prawn stock assessment was completed in 2009, using catch and standardised CPUE data to the end of 2007 and data from fishery-independent surveys [Turnbull et al. 2009]. There has been no updated assessment or CPUE standardisation since 2009. The 2009 assessment indicated that the Blue Endeavour Prawn biomass was around 80% of unfished biomass, and considerably higher than BMSY estimated to be 0.43B0. Since the 2009 assessment, effort in the fishery has been well below historic levels [Turnbull and Cocking 2022].  

Nominal CPUE for Blue Endeavour Prawns has decreased by nearly 50% in recent years, from an average of 111 kg/day for 1992 to 2003 (range 87–149 kg/day) to an average of 57 kg/day for 2009 to 2021 (range 30–117 kg/day) [Turnbull and Cocking 2022]. Nominal CPUE further decreased from 60 kg/day in 2020 to 49 kg/day in 2021 [Turnbull and Cocking 2022].  

Although declines in nominal CPUE are not conclusive evidence that the stock is depleted, they do raise concerns that warrant further investigation. Additionally, and because it relates to the utility of nominal CPUE, ABARES understands that the TSPF has changed its targeting practices in recent years to focus more heavily on the Tiger Prawn stock. This behaviour may also limit the utility of nominal CPUE as an index of abundance for the Blue Endeavour Prawn stock and add weight to the need for further investigation that demonstrates the state of the stock in relation to reference points.  

Torres Strait is a region experiencing environmental change due to climate change [Dutra et al. 2021, NESP ESCC Hub 2018], with potential implications for the productivity of fish stocks. As a significant period of time has passed since the stock assessment for Blue Endeavour Prawns, it will become increasingly difficult to assume, without an approved updated stock assessment, that productivity has remained stable and that the outcomes of the 2009 assessment remain valid.

Catches of Blue Endeavour Prawn in the TSPF over the recent decade have been quite low compared with historical highs and, with exception of 2019 (299 t), have not exceeded 200 t [D’Alberto et al. 2022]. Annual catches have decreased since then, reaching the lowest reported catch of 25 t in 2017. Reported catch was 61 t in 2021, up from 60 t in 2020.

On the basis of the evidence provided above, there is insufficient information available to confidently classify the status of this stock.  

The Torres Strait Prawn Fishery (Blue Endeavour Prawn) (Commonwealth) management unit is classified as an undefined stock.

Red and Blue Endeavour Prawn biology [Courtney et al. 1989; Kailola et al. 1993; Keating et al. 1990; Kangas et al. 2015; Somers et al. 1987; Yearsley et al. 1999]

Commonwealth – Commercial (catch). Catch is by calendar year. TSPF – Torres Strait Prawn Fishery. NPF – Northern Prawn Fishery.

Commonwealth – Indigenous (management methods). The Commonwealth Government does not manage non-commercial Indigenous fishing (with the exception of the Torres Strait). In general, non-commercial Indigenous fishing in Commonwealth waters is managed by the states or territory immediately adjacent to those waters. In the Torres Strait both commercial and non-commercial Indigenous fishing is managed by the Torres Strait Protected Zone Joint Authority (PZJA) through the Australian Fisheries Management Authority (Commonwealth), Department of Agriculture Fisheries and Forestry (Queensland) and the Torres Strait Regional Authority. The PZJA also manages non-Indigenous commercial fishing in the Torres Strait.

Commonwealth – Recreational (fishing methods). The Commonwealth Government does not manage recreational fishing. Recreational fishing in Commonwealth waters is managed by the states or territory immediately adjacent to those waters, under their management regulations.

Queensland – Indigenous (management methods). for more information see https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing 

Queensland – Commercial (Management Methods). Harvest strategies available at: https://www.daf.qld.gov.au/business-priorities/fisheries/sustainable/harvest-strategy

Queensland – Commercial (Catch). Queensland commercial and charter data has been sourced from the commercial fisheries logbook program. Further information available through the Queensland Fisheries Summary Report 

Commercial catch of Red and Blue Endeavour Prawns - note confidential catch not shown

1. AFMA 2022, ‘Northern Prawn Fishery Resource Assessment Group (NPRAG) meeting, minutes, 17 to 18 May 2022’, Australian Fisheries Management Authority, Canberra.
2. AFMA 2023, Northern Prawn Fishery Resource Assessment Group (NPRAG) meeting, minutes, 24 to 25 May 2023, Australian Fisheries Management Authority, Canberra.
3. Buckworth, RC, Hutton, T, Deng, R, Upston, J 2016, Status of the Northern Prawn Fishery Tiger Prawn fishery at the end of 2015 with TAE estimation for 2016, Australian Fisheries Management Authority, Canberra, 2016.
4. Butler, I, D'Alberto, B and Dylewski, M 2023, Northern Prawn Fishery, in Butler, I, Patterson, H, Bromhead, D, Galeano, D, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2023, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
5. Courtney, A, Dredge, M, and Masel, J 1989, Reproductive Biology and Spawning Periodicity of Endeavour Shrimps Metapenaeus endeavouri (Schmitt, 1926) and Metapenaeus ensis (de Haan, 1850) from a Central Queensland (Australia) Fishery, Asian Fisheries Science, 3: 133–147.
6. D'Alberto, B, Butler, I, and Tuynman, H, 2022, Torres Strait Prawn Fishery, in Patterson, H, Bromhead, D, Galeano, D, Larcombe, J, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2022, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
7. Deng, RA, Hutton, T, Miller, M, Upston, J, Moeseneder, C, Kompas, T & Pascoe, S 2022, ‘Agenda item 6a: Tiger prawn assessment – results (status of the Northern Prawn Fishery Tiger Prawn Fishery at the end of 2021 with TAE estimation for 2022 and 2023)’, report to the NPRAG meeting 17 to 18 May 2022, Brisbane.
8. DPIRD 2018, Exmouth Gulf Prawn Managed Fishery harvest strategy 2014–2019.
9. Dutra, L, Plagányi, E, Kenyon, R, Hutton, T, Murphy, N, Blamey, L, Edgar, S & Moeseneder, C 2021, Scoping a future project to address impacts from climate variability and change on key Torres Strait Fisheries, final report for project ‘Climate variability and change relevant to key fisheries resources in the Torres Strait’ to the Australian Fisheries Management Authority, CSIRO.
10. Fox, AR, Lovett, RA, Wickens, ME, and Hillcoat, KB 2023, Stock assessment of Queensland east coast endeavour prawns (Metapenaeus endeavouri and Metapenaeus ensis), Australia, with data to December 2021, November 2023, Fisheries Queensland, Department of Agriculture and Fisheries.
11. Kailola, PJ, Williams, MJ, Stewart, PC, Reichelt, RE, McNee, A and Grieve, C 1993, Australian Fisheries Resources, Bureau of Rural Resources and the Fisheries Research and Development Corporation, Canberra.
12. Kangas, MI, Sporer, EC, Hesp, SA, Travaille, KL, Moore, N, Cavalli, P and Fisher, EA 2015, Exmouth Gulf Prawn Managed Fishery, Western Australian Marine Stewardship Council Report Series, 1: 273 pp.
13. Keating, J, Watson, R, and Sterling, D 1990, Reproductive biology of Penaeus esculentus (Haswell, 1879) and Metapenaeus endeavouri (Schmitt, 1926) in Torres Strait, in Mellors, J (ed.), in Torres Strait prawn project: a review of research 1986–1988, Queensland Department of Primary Industries Information Series, Queensland Department of Primary Industries, Brisbane.
14. Kenyon, RA, Deng, R, Donovan, AG, van der Velde, TD, Fry, G, Tonks, M & Salee, K 2021, An integrated monitoring program for the Northern Prawn Fishery 2018–2021, final report, AFMA 2017/0819, CSIRO Oceans and Atmosphere, Brisbane.
15. NESP ESCC Hub 2018, Climate change in the Torres Strait: implications for fisheries and marine ecosystems, Earth Systems and Climate Change Hub report 4, National Environmental Science Program Earth Systems and Climate Change Hub, Australia.
16. Newman, S, J, Wise, B, S, Santoro, K, G, and Gaughan, D, J (eds) 2023, Status Reports of the Fisheries and Aquatic Resources of Western Australia 2021/22: The State of the Fisheries, Department of Primary Industries and Regional Development, Western Australia.
17. Punt, AE, Deng, R, Pascoe, S, Dichmont, CM, Zhou, S, Plagányi, É, Hutton, T, Venables, WN, Kenyon, R & van der Velde, T 2011, ‘Calculating optimal effort and catch trajectories for multiple species modelled using a mix of size-structured, delay-difference and biomass dynamics models’, Fisheries Research vol. 109, pp. 201–11.
18. Punt, AE, Deng, RA, Dichmont, CM, Kompas, T, Venables, WN, Zhou, S, Pascoe, S, Hutton, T, Kenyon, R, van der Velde, T & Kienzle, M 2010, ‘Integrating size-structured assessment and bio-economic management advice in Australia’s Northern Prawn Fishery’, ICES Journal of Marine Science, vol. 67, pp. 1785–801.
19. Somers, I, Poiner, I and Harris, A 1987, A study of the species composition and distribution of commercial penaeid prawns in Torres Strait, Australian Journal of Marine and Freshwater Research, 38: 47–61.
20. Turnbull, C & Cocking, L 2022, Torres Strait Prawn Fishery data summary 2021, Australian Fisheries Management Authority, Canberra.
21. Turnbull, C and Gribble, N 2004, Assessment of the northern Queensland Tiger and Endeavour prawn stocks: 2004 update, Department of Primary Industries and Fisheries, Brisbane.
22. Turnbull, C, Tanimoto, M, O’Neill, MF, Campbell, A & Fairweather, CL 2009, Torres Strait spatial management research project 2007–09, final report for DAFF consultancy DAFF83/06, Queensland Department of Employment, Economic Development and Innovation, Brisbane.
23. Turnbull, CT and Atfield, JC 2007, Fisheries Long Term Monitoring Program—Summary of tiger and endeavour prawn survey results: 1998–2006, Department of Primary Industries and Fisheries, Brisbane, Australia
24. Venables, W and Dichmont, C 2004, GLMs, GAMs and GLMMs: an overview of theory for applications in fisheries research, Fisheries Research, 70: 319–337.
25. Wang, N, Wang, Y-G, Courtney, AJ and O’Neill, M 2015, Application of a weekly delay-difference model to commercial catch and effort data for tiger prawns in the Queensland East Coast Trawl Fishery, PhD Thesis, University of Queensland and Queensland Government Department of Agriculture, Fisheries and Forestry.
26. Yearsley, G, Last, P and Ward, R 1999, Australian seafood handbook: domestic species, CSIRO Marine Research, Hobart.
27. Zhou, S, Hutton, T, Lei, Y, Miller, M, Van Der Velde, T and Deng, R 2022, Modelling growth of red endeavour prawns (Metapenaeus ensis) using new ELEFAN and Bayesian growth models. Final report to Australian Fishery Management Authority, Brisbane, Australia. 55 pp.
28. Zhou, S, Lei, Y, Deng, AR, Hutton, T, Miller, M & van der Velde, T 2023, Stock assessment of Red Endeavour Prawns (Metapenaeus ensis) and Blue Endeavour Prawns (M. endeavouri) in the Northern Prawn Fishery using a Bayesian approach.Final Report to Australian Fishery Management Authority. Brisbane, Australia.